package bidoutcomes

import (
	"encoding/json"
	"errors"
	"net/http"

	"github.com/go-chi/chi/v5"
	"github.com/google/uuid"

	"github.com/missionworkforce/missionmatch/internal/platform/security"
	"github.com/missionworkforce/missionmatch/internal/platform/tenant"
)

// Handler serves the M7 bid outcomes recording API: record (POST) and update (PATCH). It is mounted ONLY
// when the MM_BID_OUTCOMES_ENABLED flag is on, so the feature ships dormant; when off the routes are never
// registered and a request to them is a plain 404 from the router.
type Handler struct{ svc *Service }

// NewHandler builds the handler.
func NewHandler(svc *Service) *Handler { return &Handler{svc: svc} }

// Routes mounts the bid outcomes endpoints under the tenant scoped /api group. Recording and updating a bid
// outcome is a proposal team write action, so both are gated on slate.write (the same authority tier that
// edits a slate and generates staffing recommendations): owner, admin, and recruiter. The caller and the
// validated org come from the session resolver and RBAC middleware the group already applies, never a
// client supplied header or body field.
func (h *Handler) Routes(r chi.Router) {
	r.With(security.RequireCapability(security.CapSlateEdit)).Post("/bid-outcomes", h.record)
	r.With(security.RequireCapability(security.CapSlateEdit)).Patch("/bid-outcomes/{id}", h.update)
}

func (h *Handler) record(w http.ResponseWriter, r *http.Request) {
	var in RecordInput
	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}
	out, err := h.svc.RecordBidOutcome(r.Context(), in)
	if err != nil {
		writeErr(w, err)
		return
	}
	writeJSON(w, http.StatusCreated, out)
}

func (h *Handler) update(w http.ResponseWriter, r *http.Request) {
	id, err := uuid.Parse(chi.URLParam(r, "id"))
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid id"})
		return
	}
	var in UpdateInput
	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}
	out, err := h.svc.UpdateBidOutcome(r.Context(), id, in)
	if err != nil {
		writeErr(w, err)
		return
	}
	writeJSON(w, http.StatusOK, out)
}

// writeErr maps a service error to a status. A bad result enum or a malformed id is a 422, a missing row is
// a 404, an unscoped request is a 403, and an unconfigured database is a 503; everything else is a 500 with
// no internal detail leaked.
func writeErr(w http.ResponseWriter, err error) {
	switch {
	case errors.Is(err, ErrInvalidResult):
		writeJSON(w, http.StatusUnprocessableEntity, map[string]string{"error": "result must be one of win, loss, no_bid, pending"})
	case errors.Is(err, ErrInvalidID):
		writeJSON(w, http.StatusUnprocessableEntity, map[string]string{"error": "an id field must be a uuid"})
	case errors.Is(err, ErrNotFound):
		writeJSON(w, http.StatusNotFound, map[string]string{"error": "bid outcome not found"})
	case errors.Is(err, tenant.ErrNoTenant):
		writeJSON(w, http.StatusForbidden, map[string]string{"error": "no validated tenant"})
	case errors.Is(err, ErrNoDatabase):
		writeJSON(w, http.StatusServiceUnavailable, map[string]string{"error": "database not configured"})
	default:
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "internal error"})
	}
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(v)
}